This week we spent some time interviewing Jeff Dilts, the senior director of marketing and product management for Star Trac, concerning the launch of the new Star Trac Spinner® Blade Ion, due out later this year.
CS: How is the user’s power measured by the Spinner® Blade Ion?
JD: The system measures the tangential (cross directional) force the brake pad applies to the Spinner Blade Ion’s flywheel through a load cell. Knowing the tangential force component, the resulting restive torque and the rider’s cadence, allows the computer to provide an accurate rider power output.
CS: How does this compare to actual road bike power measurements from companies like SRM and Power Tap?
JD: The best cycling power measurement systems use strain gauges to measure the reciprocating crank load cycles at a measurement point on the bike; the predominate measurement points are located at the crank, the cassette or the pedal. The computer then takes these reciprocating loads and their angular speeds, and calculates/averages the power output with mathematical formulas.
CS: How do you validate the accuracy of Spinner Blade Ion’s strain gauge technology?
JD: We validate the accuracy through a comparison test, by measuring the difference between the input power to drive the bike, compared to the resulting power output measured by the computer. We apply input power through a motor coupled to the crank, with a measurement device called a Dynamometer. The Dynamometer offers measurements with 99.5 percent accuracy. We compare this power input to the computer’s measured power output. By knowing the difference between the dynamometer power input and watts computer power output, we can validate the accuracy of the system.
CS: How does the Spinner Blade Ion generate its own power?
JD: The system incorporates a permanent magnet generator system. As the rider inputs mechanical energy into the pedals, the flywheel and a set of magnets rotate in close proximity to a stator filled with copper windings. The magnetic flux of the rotating magnets about the stator causes electromagnetic induction, creating a low power energy source to operate the computer and load cell.
CS: Why is the Spinner Blade Ion an integrated power system vs. a bolt-on backwards compatible computer?
JD: We wanted to provide a complete solution, where we measured true power output, and we set a goal to resolve the environmental waste associated with constant battery replacement. We solved this problem by taking a holistic approach to the design, and incorporated the generator as part of the flywheel, and interconnecting this power to the components. It was not realistic to deploy a kit that would fit onto already built bikes, because it would mean replacing the flywheel and externally wiring the unit.
CS: What other tracking or monitoring devices will the Spinner Blade Ion power computer talk to? How can I track and monitor my work?
JD: The system is Ant+ compatible and will communicate power, heart rate, distance and calories to a paired Ant+ device. Pairing an Ant+ device is as simple as starting your ride, and bringing your Ant+ device in close proximity to the Ant+ badge, and allowing the computer and the user’s device (watch, phone) to couple. Once coupled, the devices hold a digital connection and data is transferred from the computer to the user’s device through the workout.
CS: Who was the main designer and engineer in constructing the new Spinner Blade Ion, and what’s their background?
JD: Star Trac works very closely with its partner in Spinning®, owned by Mad Dogg Athletics, the founders of the original Spinning Group Cycling program. The design of our Spinning products are truly a team effort and include industrial designers, engineers, Master Spinning Instructors, project and product managers with specific expertise in biomechanics and cycling design; and, finally, John Baudhuin himself, the owner of Mad Dogg Athletics/Spinning. The development process includes a focus group made up of both cycling enthusiasts and group cycling novices, elite athletes and new-to-exercise beginners. We have a power voice of customer approach that truly evolves our end users in the outcome of our products.
CS: Why did Star Trac decide to redesign the Spinner Blade Ion?
JD: As mentioned above, the Spinner Blade Ion is a Spinner Blade that has been integrated with the ION Power Measurement Technology — it is its own product built on the platform of our most popular Spinner (the Spinner Blade)
CS: Where did the new concept come into fruition?
JD: As mentioned, as our customer’s interest grew regarding power (watts) training on group cycles, our desire to deliver the best solution in the group cycling category grew. We take our number one market share position very seriously in the category, and when we design new innovations, we strive to maintain this up-front position.
CS: When will the new Spinner Blade Ion be ready for purchase?
JD: We are currently beta testing with actual locations throughout Southern California and our target launch date is March, 2013.
